Drier and cooler for grain or the like



a m z m m my m 5 .v m x 2 a m QM G. D- ARNOLD DRIER AND COOLER FOR GRAINOR THE LIKE May 15, 1951 Filedpec.

May 15, 1951 G. D. ARNOLD DRIER AND COOLER FOR GRAIN OR THE LIKE 2Sheets-Sheet 2 Filed Dec. 11, 1946 Patented May 15, 1951 DRIER ANDCOOLER FOR GRAIN OR THE LIKE Gerald D. Arnold, Wauwatosa, Wis.

Application December 11, 1946, Serial No. 715,393

8 Claims.

This invention relates to improvements in dryer and cooler for grain orthe like.

Rotary, direct heat dryers for forage crops have not been satisfactoryfor the purpose of drying grain, shelled corn, or like products, becausethe grain is not held within the drum for a sufficient length of time toaccomplish proper dehydration. Furthermore, no satisfactory method hasbeen provided for quickly cooling the hot, dehydrated material in thesame apparatus.

To successfully dry grain or shelled corn it is necessary to heat up theproduct relatively slowly, before very much drying action takes place.This heating up cannot be accomplished with too high a temperature orthe grain will become case hardened to seal the moisture in. Therefore,the product must first be heated up slowly to boil moisture out of thegrain particles so that the heated air currents within the dryer cancarry this moisture off. To attempt to dry grain without a preheatingperiod would require the use of a substantially lower temperature withinthe dryer, and a reduction in the velocity of the air currents. This,however, would materially reduce the capacity and render the dryerimpractical.

It is a general object of the present invention to provide an improveddryer for grain or the like wherein means is provided for mechanicallyretarding the flow of the grain, particularly through the insidecylinder so that a heating up period is provided to effectively drivethe moisture out of the interior of the grain whereby the air currentsmay be effective in carrying said moisture away.

A further object of the invention is to provide an improved dryer andcooler particularly, but not exclusively adapted for the drying ofgrain, comprising a plurality of concentric drums, wherein the annularchamber within the outermost drum is so utilized as to cool the hotdehydrated material before the latter is discharged, and wherein theheat which is picked up by the cooling air is utilized in the dryer fordrying purposes thereby reducing fuel consumption, the pre heated airbeing very effective when acting on grain or shelled corn, to start theheating up process.

A further object of the invention is to provide a dryer and cooler asabove described wherein a single fan serves to create movement of aircur rents for both the cooling and drying processes.

Other objects of the invention are to provide a dryer and cooler forgrain or the like which is relatively simple in construction, which hasa minimum number of parts, and which is well adapted for the purposedescribed.

With the above and other objects in view, the invention consists of theimproved dryer and cooler for grain or the like, and all its parts andcombinations, as set forth in the claims, and all equivalents thereof.

In the accompanying drawings, illustrating one complete embodiment ofthe preferred form of the invention, in which the same referencenumerals designate the same parts in all of the views:

Fig. 1 is a vertical, longitudinal, sectional view through the improveddryer and cooler, an inter" mediate portion of the unit being brokenaway;

Fig. 2 is a sectional view taken approximately on the line 2-2 of Fig.1;

Fig. 3 is a sectional View taken on the line 33- 3 of Fig. 1;

Fig. 4 is a perspective view of one type of retarding plate attachment;and

Fig. 5 is a similar view of a slightly different type of retardingflight attachment.

Referring more particularly to the drawings, the numeral l0 designates agenerally cupshaped, nonrotatable head portion having a closed outer endH formed with an opening l2 for receiving the nozzle l3 of an oil burnerM or other suitable source of heat.

The open end of the head member is provided with a projecting annularflange I5 within which the end of an outer cylinder I6 is rotatable.Said end of the cylinder may have its peripheral edge formed with areversely bent part ll for rotation within an annular space formedbetween the flange 1 5 and a sealing ring [8. Any other suitable type ofrotary seal may be utilized.

The bottom of the head member In has downwardly converging walls leadingto an opening I 9, and the latter communicates with a discharge tube 20.Any suitable means may be utilized in the tube 20 for discharging theproduct from the discharge end 2!. In the drawing there is illustrated ascrew 22 formed by a spiral blade connected to a rotatably mounted shaft23. The shaft may be rotated by transmitting power from any suitablesource to a pulley 24.

A receivin hopper 25, which may have an air excluding metering valve 26associated therewith, is adapted to direct the grain or other materialto be dried, in a substantially air fr'ee condition, into a chute 2?.The open end 28 of the chute directs the material into the open end ofthe drying chamber 29.

The drying chamber is formed by an inner cylinder 30 which is positionedconcentrically within the outer cylinder I5. The cylinder 30 is chamber33 which is formed within the outer cylinder. This may be accomplishedby having the cylinder Si; provided with a double wall and by having anintervening layer of insulating material 34. In lieu of the insulatingmaterial a vacuum or dead air space may be utilized.

Projecting into the outer cylinder 56, and cooperable with the outer endof the inner cylinder in such a way as to substantially exclude air is ahousing 35 forming a transfer chamber 35. The

closed end 3? of the housing 35 may have a projecting tubular portion 38which is open as at 39. A suction fan 40 is suitably supported adjacentthe opening 39.

The bottom of the transfer chamber 36 has downwardly converging sidewalls 4! leading to one or more transfer troughs 42. Each transfertrough has a screw d3 therein which may be suitably driven bytransmitting motion to pulleys M.

The inner ends of the troughs 42 merge into tubular extensions :35, andthe latter have open ends it positioned within the cylinder is fordepositing dried grain or other material in the cooling chamber 33.

The inner surface of the cylinder 56 and the outer surface of thecylinder 30 are provided with suitable flights such as the lineal,transversely curved flights ll. Similar lineal flights 48 are connectedto the inner surface of the inner cylinder 38. These flights may haveangled a discharge ends 49.

In order to retard the flow of material through the drying chamber 29,attachable segmental flights 5 are utilized. These segmental flights arebest illustrated in Figs. 2, 4 and 5. The type of segment illustrated inFig. 4 has a longitudinal attachment flange 5i shaped transversely so asto fit the concave side of one of the longitudinal flights I38 as isclear from Fig. 2. The attachable segment of Fig. 5 has its flange 52shaped transversely to cooperate with the convex side of one of thelongitudinal flights 48. The segments are suitably bolted or riveted tothe lineal flights dB. The segmental flights 5b are generaly L- shapedin cross-section as is clear from Figs. 4 and 5, and comprise onetriangular Wall 53 and a second, substantially triangular wall 54positioned at an angle to the wall 53. The narrow ends of the walls arejuxtaposed so that the entire member is of tapering cross-section. Thewall portions 54 are also preferably transversely concave.

For grain drying purposes the segments are connected to the linealflights 48 in the general manner indicated in Fig; 1 with the largerends facing the receiving end of the drying chamber. Any'desired numberof the segments may be utilized on one of the lineal flights, and theymay be spaced close together or far apart according to requirements. Itis also desirable, in the drying of'certaln products, to stagger theattachable segments which are on one lineal flight with respect to theattachable segments on an adjacent lineal flight. If desired, segmentalflights may also be used on the lineal flights ll in the coolingchamber.

Operation In use of the improved dryer and cooler it is first necessaryto impart rotating movement to the concentric cylinders it and 3G by anysuitable means. It is also necessary to have the suction fan at inoperation. The blast of hot gases discharged from the nozzle 53,together with air drawn in or around the nozzle from the cooling chamber33 is discharged into the inner end of the inner cylinder 38. Into thismixture of gases, the wet material to be dried s fed from the opening 2%of the chute 2?. As the drum rotates, those particles of material to bedried which drop to the bottom of the cylinder 30 are carried by thelineal flights it toward the top of the cylinder where they ultimatelydrop off of the edges of said flights. The lighter particles of materialwill tend to be advanced through the cylinder, by the air currentstherein, more rapidly than will the heavier particles. As the heavierparticles roll off of the edges of the longitudinal flights 58, many ofthem will be intercepted by the attachable segments 56, and the shape ofsaid segments will tend to retard the falling movement of the grain andwill also make the particles flow backwards, or counter to the directionof flow of air within the cylinder. This action eliectively retards themovement or the particles of grain or other material through the drumand provides a necessary preheating period for products such as grain orshelled corn.

After the particles have become thoroughly dry they will eventually bedischarged into the transfer chamber as and will fall by gravity intothe troughs 2. The screws 43 will then move the dried material towardand through the openings' it and into the cooling chamber 33. Theconstruction of the screw l3 and extensions 15 is such as tosubstantially prevent the entrance of heated air into the coolingchamber.

In the cooling chamber the particles of grain or other material arepicked up by the lineal flights ll and ultimately dropped to fall backtoward the bottom. At the same time fresh air from the outside entersthe cooling chamber 33 at the open end thereof, and moves longitudinallytherethrough and serves to cool the particles.

Movement of the cooling air through the cooling chamber in the directionindicated by the arrows is produced by the same fan is which createsmovement in the drying chamber. Inasmuch as the cooling air picks upheat from the dried particles, it is delivered in a preheated conditioninto the receiving end of the drying chamber. Thus, the same air is usedfor both cooling and drying and the movement of the air in both thecooling and drying chambers is pro duced by the same suction fan. Thecooled and dehydrated product is ultimately discharged from the coolingchamber through the opening it and into the discharge tube 25).

The segmental flights 53 when used as illustrated, make the dryerparticularly adapted for the drying of grain or shelled corn. However,the dryer and cooler may obviously be used for the drying of a varietyof products either with or without the attachable segments 58 dependingupon the particular requirements.

The present application deals with the use of the segmental flights onlyin combination with the type of apparatus claimed herein. Theconstruction of the segmental flights per se forms the subject matter ofa companion application.

If desired, more than two concentric cylinders may be employed fordehydrating as in my prior Patent No. 1,988,678.

Various other changes and modifications may be made without departingfrom the spirit of the invent-ion, and all of such changes arecontemplated, as may come within the scope of the claims.

That I claim is:

1. In a dehydrating apparatus, a rotatable inner cylinder forming adrying chamber, a cylinder surrounding said inner cylinder and rotatabletherewith and housing an annular cooling chamber, there being an openingfor cooling communicating at one end with said cooling chamber, means atthe opposite end of the apparatus for introducing material to be driedinto said drying chamber, means for delivering heat to said drying chambr, means connecting said drying chamber with said cooling chamber fordirecting material which has been dried from said drying chamber intosaid cooling chamber, said means including a transfer tube and a screwof substantially the same diameter as the internal diameter of saidtransfer tube rotatable therein in a direction to cause movement ofmaterial into said cooling chamber.

2. In a dehydrating apparatus, a rotatable cylinder forming a dryingchamber, a larger cylinder surrounding said inner cylinder and rotatabletherewith and housing an annular cooling chamber, there being an openingfor cooling air communicating at one end with said cooling chamber,means at the opposite end of the apparatus for introducing material tobe dried into said drying chamber, means for delivering heat to saiddrying chamber, means connecting said drying chamber with said coolingchamber for directing material which has been dried from said dryingchamber into said cooling chamber, said means including a transfer tube,a screw of substan tially the same diameter as the internal diameter ofsaid transfer tube rotatable therein in a direction to cause movement ofmaterial into said cooling chamber, and means for causing cooling air tocirculate from said cooling chamber into said drying chamber.

3. In a dehydrating apparatus, a rotatable inner cylinder forming adrying chamber, a larger cylinder surrounding said inner cylinder androtatable therewith and housing an annular cooling chamber, a fixed headhaving an open end within which one end of said outer cylinder isrotatably positioned, said COOllllg chamber having an open ing forcooling air communicating therewith, means connected to said head fordelivering heat to said drying chamber, means connected to said head forintroducing material to be dried into said drying chamber, a transferhousing at the opposite end of the apparatus from said head into whichsaid inner cylinder rotatably projects, a suction fan connected to saidtransfer housing, means for directing material from said transferhousing into said annular cooling chamber, and discharge means in theloWer portion of said head into which cooled material from said coolingchamber is directed.

4. In a dehydrating apparatus, a rotatable inner cylinder forming adrying chamber, a larger cylinder surrounding said inner cylinder androtatable therewith and housing an annular cooling chamber, said coolingchamber having an opening for cooling air communicating therewith, meansfor delivering heat into one end of said to be dried into the same endof said drying chamber, a transfer housing at the opposite end of theapparatus with which said inner cylinder is rotatably and sealinglyconnected, a suction fan connected to said transfer housing for movingmaterial through the drying chamber, and means for directing materialfrom said transfer housing into theadjacent end of said annular coolingchamber while closing said end to the action of said suction fan, and ahead forming a direct communication between the other end of saidcooling chamber and the material feed end of said drying chamber wherebythe suction fan also aids in moving material through the coolingchamber.

5. In a dehydrating apparatus, a rotatable inner cylinder forming adrying chamber, a larger cylinder surrounding said inner cylinder androtatable therewith and housing an annular cooling chamber, said coolingchamber having an opening for cooling air communicating therewith, meansfor delivering heat into one end of said drying chamber, means forintroducing material to be dried into the same end of said dryingchamber, a transfer housing at the opposite end of the apparatus withwhich said inner cylinder is rotatably and sealingly connected, asuction fan connected to said transfer housing for moving materialthrough the drying chamber, means for directing material from saidtransfer housin into one end of said annular cooling chamber whileclosing said end to the action of said suction fan, there beingcommunication between the other end of said cooling chamber and saiddrying chamber whereby the suction fan also aids in moving materialthrough the cooling chamber, and means for discharging the material fromsaid last-mentioned end of the cooling chamber.

6. In a dehydrating apparatus, a rotatable inner cylinder forming adrying chamber, a larger cylinder surrounding said inner cylinder androtatable therewith and housing an annular cooling chamber, a fixed headhaving an open end with which one end of said outer cylinder isrotatably and sealingly connected, said head forming a directcommunication between one end of said drying chamber and the adjacentend of the cooling chamber said cooling chamber having an opening forcooling air communicating therewith, means connected to said head fordelivering heat to said drying chamber, means connected to said head forintroducing material to be dried into the end of said drying chamberadjacent said head, a transfer housing at the opposite end of theapparatus from said head to which said inner cylinder is rotatably andsealingly connected, a suction fan connected to said transfer housingfor moving material through the drying chamber, and means for directingmaterial from said transfer housing into the adjacent end of saidannular cooling chamber while closing said end to the action of saidsuction fan, the direct communication between the other end of saidcooling chamber and the feed end of said drying cham ber permitting thesuction fan to also aid in moving material through the cooling chamber.

"1. In a dehydrating apparatus; a rotatable cylinder forming a dryingchamber; a, second cylinder of larger diameter surrounding said firstmentioned cylinder, said cylinder being rotatable with said firstcylinder and forming therebetween an annular cooling chamber having acooling air inlet opening; a head forming a direct communication betweenone end of the drying chamber drying chamber, means for introducingmaterial is and the adjacent end of the annular cooling chamber; meansfor delivering heat to said drying chamber; means for introducingmaterial to be dried into said drying chamber adjacent said head; atransfer housing communicating with the end of the inner cylinderopposite said head; means for causing cooling air to circulate from saidcooling chamber through said head and into said drying chamber; andmeans for directing material from said transfer housing into theadjacent end portion of said annular cooling chamber while preventingany substantial air flow from said housing into said cooling chamber.

8. In a dehydrating apparatus; a rotatable cylinder forming a dryingchamber; a second cylinder of larger diameter surrounding said firstmen-' tioned cylinder, said cylinder being rotatable with said firstcylinder and forming therebetween an annular cooling chamber having acooling air inlet opening; a head forming a direct communication betweenone end of the drying chamber and the adjacent end of the annularcooling chamber; means for delivering heat to said drying cham'- ber;means for introducing material to be dried into said drying chamberadjacent said head; a

transfer housing communicating with the end of the inner cylinderopposite said head; means for causing cooling air to circulate from saidcooling chamber through said head and into said drying chamber; meansfor directing material from said transfer housing into the adjacent endportion of said annular cooling chamber while preventing any substantialair flow from said housing into said cooling chamber; and means in saidhead for receiving the dried and cooled material from said coolingchamber and for discharging said material from said head. 7

GERALD D. ARNOLD.

No references cited.

